Soft magnetic properties of nanocrystalline Fe100−xSix (15<x<34) alloys

Nanocrystalline Fe 100-x Si x (15 < x < 34) alloys have been prepared by melt spinning with high cooling rate. We have found by X-ray diffraction that the basic cubic symmetry could be extended up to 34at% Si. Around the composition of Fe 2 Si, a single-phase metastable B2 structure was found. If the quenching is not properly conducted, traces of hexagonal Fe 5 Si 3 appear, which is detrimental to the soft magnetic properties. Our M S , T C , K, D sp and p results complement the existing (up to 25at%) data and their soft magnetic properties are herein presented for the first time, The frequency dependence of the complex permeability in this high Si content region is comparable with that of NiZn ferrite.